--- /dev/null
+<?php
+
+namespace Drupal\Tests\comment\Kernel;
+
+use Drupal\comment\Entity\CommentType;
+use Drupal\Component\Utility\Unicode;
+use Drupal\Core\Database\Database;
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
+use Drupal\Core\Entity\Entity\EntityViewMode;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests integration of comment with other components.
+ *
+ * @group comment
+ */
+class CommentIntegrationTest extends KernelTestBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public static $modules = ['comment', 'field', 'entity_test', 'user', 'system', 'dblog'];
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function setUp() {
+ parent::setUp();
+ $this->installEntitySchema('entity_test');
+ $this->installEntitySchema('user');
+ $this->installEntitySchema('comment');
+ $this->installSchema('dblog', ['watchdog']);
+
+ // Create a new 'comment' comment-type.
+ CommentType::create([
+ 'id' => 'comment',
+ 'label' => $this->randomString(),
+ ])->save();
+ }
+
+ /**
+ * Tests view mode setting integration.
+ *
+ * @see comment_entity_view_display_presave()
+ * @see CommentDefaultFormatter::calculateDependencies()
+ */
+ public function testViewMode() {
+ $mode = Unicode::strtolower($this->randomMachineName());
+ // Create a new comment view mode and a view display entity.
+ EntityViewMode::create([
+ 'id' => "comment.$mode",
+ 'targetEntityType' => 'comment',
+ 'settings' => ['comment_type' => 'comment'],
+ ])->save();
+ EntityViewDisplay::create([
+ 'targetEntityType' => 'comment',
+ 'bundle' => 'comment',
+ 'mode' => $mode,
+ ])->setStatus(TRUE)->save();
+
+ // Create a comment field attached to a host 'entity_test' entity.
+ FieldStorageConfig::create([
+ 'entity_type' => 'entity_test',
+ 'type' => 'comment',
+ 'field_name' => $field_name = Unicode::strtolower($this->randomMachineName()),
+ 'settings' => [
+ 'comment_type' => 'comment',
+ ],
+ ])->save();
+ FieldConfig::create([
+ 'entity_type' => 'entity_test',
+ 'bundle' => 'entity_test',
+ 'field_name' => $field_name,
+ ])->save();
+
+ $component = [
+ 'type' => 'comment_default',
+ 'settings' => ['view_mode' => $mode, 'pager_id' => 0],
+ ];
+ // Create a new 'entity_test' view display on host entity that uses the
+ // custom comment display in field formatter to show the field.
+ EntityViewDisplay::create([
+ 'targetEntityType' => 'entity_test',
+ 'bundle' => 'entity_test',
+ 'mode' => 'default',
+ ])->setComponent($field_name, $component)->setStatus(TRUE)->save();
+
+ $host_display_id = 'entity_test.entity_test.default';
+ $comment_display_id = "comment.comment.$mode";
+
+ // Disable the "comment.comment.$mode" display.
+ EntityViewDisplay::load($comment_display_id)->setStatus(FALSE)->save();
+
+ /** @var \Drupal\Core\Entity\Display\EntityViewDisplayInterface $host_display */
+ $host_display = EntityViewDisplay::load($host_display_id);
+
+ // Check that the field formatter has been disabled on host view display.
+ $this->assertNull($host_display->getComponent($field_name));
+ $this->assertTrue($host_display->get('hidden')[$field_name]);
+
+ // Check that the proper warning has been logged.
+ $arguments = [
+ '@id' => $host_display_id,
+ '@name' => $field_name,
+ '@display' => EntityViewMode::load("comment.$mode")->label(),
+ '@mode' => $mode,
+ ];
+ $logged = (bool) Database::getConnection()->select('watchdog')
+ ->fields('watchdog', ['wid'])
+ ->condition('type', 'system')
+ ->condition('message', "View display '@id': Comment field formatter '@name' was disabled because it is using the comment view display '@display' (@mode) that was just disabled.")
+ ->condition('variables', serialize($arguments))
+ ->execute()
+ ->fetchField();
+ $this->assertTrue($logged);
+
+ // Re-enable the comment view display.
+ EntityViewDisplay::load($comment_display_id)->setStatus(TRUE)->save();
+ // Re-enable the comment field formatter on host entity view display.
+ EntityViewDisplay::load($host_display_id)->setComponent($field_name, $component)->save();
+
+ // Delete the "comment.$mode" view mode.
+ EntityViewMode::load("comment.$mode")->delete();
+
+ // Check that the comment view display entity has been deleted too.
+ $this->assertNull(EntityViewDisplay::load($comment_display_id));
+
+ /** @var \Drupal\Core\Entity\Display\EntityViewDisplayInterface $display */
+ $host_display = EntityViewDisplay::load($host_display_id);
+
+ // Check that the field formatter has been disabled on host view display.
+ $this->assertNull($host_display->getComponent($field_name));
+ $this->assertTrue($host_display->get('hidden')[$field_name]);
+ }
+
+}